Relationship between peripheral and intracoronary blood flow in patients with angina and non-obstructive coronary arteries.

Coronary vasomotor dysfunction, an important underlying cause of angina and non-obstructive coronary arteries (ANOCA), encompassing coronary vasospasm, coronary endothelial dysfunction and/or coronary microvascular dysfunction, is clinically assessed by invasive coronary function testing (ICFT). As ICFT imposes a high burden on patients and carries risks, developing non-invasive alternatives is important. We evaluated whether coronary vasomotor dysfunction is a component of systemic microvascular endothelial and smooth muscle dysfunction, and can be detected using laser speckle contrast analysis (LASCA).